History tells us that amidst the immediate panic of a nuclear attack/accident in an urban area, tens-to-hundreds of thousands of panicked people demanding to be evaluated for exposure will likely overwhelm our emergency care system and consequently jeopardize effective triage and treatment of those whose lives are imminently in danger. A method for screening the panicked masses for exposure, allowing us to rapidly reassure the unexposed and to retain only those individuals for whom immediate intervention is required, would help alleviate the burden on our emergency systems. In this proposal, we will apply a proteomic biomarker discovery pipeline that we have already shown to be effective to discover radiation-responsive proteins in saliva. We will develop Enzyme-Linked ImmunoSorbent assays (ELISAs;a conventional protein diagnostics format) for detection of salivary radiation biomarkers. These ELISAs will be characterized with respect to their dose and time course of activation. By the end of this proposal, these assays can be converted into a point-of- care diagnostic for radiation exposure that can be stockpiled and distributed at emergency facilities and self- administered by potential victims by licking a diagnostic test strip. Because many individuals will not have been exposed, this will dramatically decrease the number of individuals requiring more intensive intervention from the health care system. Specific Aim 1: Identify candidate salivary radiation biomarkers using genomic and proteomic technologies in the well-established canine model of radiation exposure Specific Aim 2: Verify that salivary radiation biomarkers discovered in the canine model are also present in human saliva post total body irradiation (TBI) Specific Aim 3: Develop stockpile-able Enzyme-Linked ImmunoSorbent Assays (ELISAs), similar to the over- the-counter pregnancy test, for 1-3 salivary radiation biomarkers and characterize these assays on human and canine saliva samples procured pre- and post-TBI History tells us that amidst the immediate panic of a nuclear attack/accident in an urban area, tens-to-hundreds of thousands of panicked people demanding to be evaluated for exposure will likely overwhelm our emergency care system and consequently jeopardize effective triage and treatment of those whose lives are imminently in danger. A method for screening the panicked masses for exposure, allowing us to rapidly reassure the unexposed and to retain only those individuals for whom immediate intervention is required, would help alleviate the burden on our emergency systems. In this proposal, will develop a saliva-based test for exposure to radiation that can be distributed at emergency facilities and self-administered by potential victims by licking a diagnostic test strip. Because many individuals will not have been exposed, this will dramatically decrease the number of individuals requiring more intensive intervention from the health care system.